Medallia is the more common of the two in our index: it runs on 108 websites against 6 for Riddle. Counts come from real scans of each site's home page, not vendor claims, and cover the sites in TechLookup's index rather than the whole web.
Medallia (formerly Kampyle) is a complete customer feedback platform that helps digital enterprises listen, understand, and act across all digital touch-points.
Riddle is a platform enabling creation of lists, polls, and quizzes.
Within the surveys sites we have indexed, Medallia holds 10% and Riddle 0.6%.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.